Does any body have experience with drug selection on transfected CHO cells?
I transfected the cell with lacSwitch vectors (i.e. the p3'SS with LacI gene and
Hygromycin gene, and pOPRSViCAT with G418 gene and LacZ operator). My control
transfection (pOPRSV with LacZ insert) gives >15% blue cells in x-gal assay. By
following stratagene protocol, I plated 1000cell/100mm dish before adding drug the
next day [Hygromycine]=300ug/ml [Geneticin]=400ug/ml either single drug or both. all
the cells look sick, if I plate the cells at density 50X higher, there are many
surviving colonies but impossible to pick up single colony.